Automatic feeding apparatus of the cutter saddle in gear shaper



Nov. 23, 1965 RlSAKU KONDO 3,218,932

AUTOMATIC FEEDING APPARATUS OF THE CUTTER SADDLE IN GEAR SHAPER INV ENTOR Risa/Va ffomda BY J ATTORNEY Nov. 23, 1965 RlSAKu oN o 3,218,932

AUTOMATIC FEEDING APPARATUS OF THE CUTTER SADDLE IN GEAR SHAPER FiledNov. 13. 1961 2 Sheets-Sheet 2 4 III INVENTOR Ez'Ja/Z'u ffcwdo ATTORNEYUnited States Patent 3,218,932 AUTOMATIC FEEDING APPARATUS OF THE CUTTERSADDLE IN GEAR SHAPER Risaku Kondo, 142 Z-chome, Kosugi-goten-machi,Kawasaki, Japan Filed Nov. 13, 1961, Ser. No. 151,716 1 Claim. (Cl. 907)The present invention relates to automatic feeding ap paratus of thecutter saddle in a gear shaper in which said saddle is moved by oilhydraulic pressure quickly at the preliminary stroke of the cutterapproaching the work and also at the retire stroke withdrawing thecutter from the work when the cutting has been completed.

Intermediate of the preliminary stroke and the retire stroke the cuttersaddle is made to do feeding motion during cutting action with positivedrive by such mechanism as toothed gear, cam, etc., the interchangebetween such different modes of transmission being accomplished by limitswitches and their individual actuating means.

The principal object of my invention is to obtain a thoroughly automaticapparatus which may be substituted for hand working, upon which thedisplacement of the cam operating the cutter saddle had been heretoforerelied upon, consequently to gain a general advantage produced by theincrease of working efiiciency.

Another object of my invention is to obtain an eifective apparatus inwhich the idle time of the working is substantially saved at thepreliminary or approach stroke, in which the saddle brings the cutter tothe cutting position; and at the terminal or retire stroke, in which thesaddle withdraws the cutter from the work to the retired position forchanging to new uncut work. It is not required that the saddle moveprecisely during such time saving preliminary and terminal strokes andtherefore fluid pressure changes may cause such movement; but it isrequired that precision and stability are secured during theintermediate cutting stroke and this latter requirement is obtained bymy positive cutter drive. Therefore, both requirements are within theobjects of my invention.

These and more detailed and specific objects will be disclosed in thecourse of the following specification, reference being had to theaccompanying drawings, in which:

FIG. 1 is a side elevational view as viewed from operators position.

FIG. 2 is a fragmentary end elevation looking from the right of FIG. 1.

FIG. 3 is a horizontal section view taken on the lines of 33 of FIG. 2.

FIG. 4 is a section elevation view on the lines 44 of FIG. 1.

FIG. 5 is an enlarged detailed elevation view of the clutch as seen inFIG. 4.

FIG. 6 is a schematic bottom view showing the arrangement of gears 48,50 and 51 on shafts 37, C and 53 respectively. The gears shown areimmediately to the left of gears 54 and 55 in FIGS. 1 and 3. The upwarddirection of the sight lines for FIG. 6 is shown by the arrows 6.6 ofFIG. 1, and

FIG. 7 a plat diagram illustrating the motions of the cutter saddle andthe cam which controls the cut of the cutter.

In the drawings, 11 is a horizontally slidable saddle movable left andright in FIG. 2, and carrying a vertical cutter spindle. The spindle issupported about a vertical-axis hearing held at the right side of thesaddle as viewed in FIG. 1. The cutter spindle and bearing are not shownon the drawings. The cutter spindle with the cutter afiixed to its lowerend, makes rotation and also vertical reciprocation, and is driven by aspecial mechanism to make the cutter cut the teeth on the work piece.

Patented Nov. 23, 1965 Since the cutter and driving mechanisms are notin the scope of the present invention, they are neither shown in thedrawings nor are they here explained in detail.

12 is a transmission bar, one end of which is connected to the cuttersaddle 11 with a screw joint 12' to make its elfective lengthadjustable, while the other end provided with a roll 13 is made to touchupon the surface of the cam 14 which controls the movement of thetransmission bar 12 and therefore that of the cutter saddle from oneside. For the same purpose the rack 12 is provided at the lower side ofthe transmission bar 12 to be in gear with the segment teeth 16rotatably supported at the shaft 15, and these segment teeth areactuated to rotate anti-clockwise by a suitable means e.g. by a springwound around the shaft 15, so that the roll 13 at the end of thetransmission bar touches the surface of the cam 14 during the time thecutter is acting upon the work. 17 is a stop pin fixed on a part of theframe by which the segment teeth 16 are made to stand still at the veryposition when the roll 13 at the end of the transmission bar has movedwith the rack 12" apart from the segment teeth 16 leftward to the retirestroke end 13 as seen in dashed lines in FIG. 2 together with the saddle11 by the action of the oil cylinder 18. Thus the rack 12" of thetransmission bar can again enter into gear with the segment teeth 16when it comes back rightward toward the work in the beginning of thenext cutting cycle. 18 is an oil cylinder which moves the cutter saddlerightward or leftward with its piston rod, attached directly to thecutter saddle, at the beginning and last of one cycle of working. 19 and20 are working bars to actuate limit switches. Bar 19 first brakes theoil cylinder 18, 20 then cuts off the oil pressure to make that cylinder18 powerless and at the same time starts the oil cylinder 26 (see points2, 3 on Sdll curve herebelow). This is done when the transmission barcarrying the cutter saddle has been moved rightward and the cutterapproaches its cutting position.

Since the cam 14 has duty to control the movement of the cutter saddleas well as the cutter, it must have different shape according to theform and dimension of tooth to be cut as well as the mode of workinge.g. two step cutting or three step cutting, so that it must be fixed onthe cam holder 22 changeably eg by means of bolts. This cam holder 22,being provided with an anti-friction metal 23 in the side, is made tomove up and down, sliding vertically in the space bounded by the frame24 and a guide plate 25, fixed thereto, actuated by the piston rod 26 ofanother oil cylinder 26 through the bracket 27 fixed thereto.

Moreover at the upper part of this cam holder 22, there is provided acam 28 and there is also provided a rack 29. The cam 28 is to move theshifter of the clutch which is hereinafter explained, while the rack 29,being put in gear with a toothed wheel 30 fixed on the shaft 37, drivessaid toothed wheel 30 when the cutter saddle is moved by the oilpressure in 18. At another time the rack 29 is driven by the toothedwheel 30 when the cutter saddle is moved with positive drive such as bytoothed gearing 16, 12.

When the cam holder 22 is raised upward by the oil cylinder 26, the pushrod 31 connecting at the lower end of the lever 32 moves leftward,moving the upper end of the lever 32 rightward through its fulcrum. Bythat motion of the lever 32, the acting rod 33 moves rightward actuatinga limit switch to brake the oil cylinder 26. Thus the oil cylinder 26 isprepared to become powerless by being cut olf from the oil pressure.

Spaced from inclined lever 32, there is provided an inclined shifterlever 34, the latter (34) pivoted at the horizontal fulcrum pin 34' onthe frame (see FIG. 1).

The upper end of 34 is loosely connected within a forked end ofhorizontal lever 34", which latter lever (34") is pivoted by a verticalpivot at an intermediate point to the frame. The upper end of the lever32 is likewise loosely connected within another forked end of lever 34";so that when the top of lever 32 inclines rightward, then the top of theother shifter lever 34" inclines leftward pulling the cap 34' to theright (in FIG. 1) by the two lower ends of the shifter lever 34.

Now since the cap has a conical inner surface, it presses the ends 35and 35 of the pawls 35 and 35' at the opposite side of the fulcrums 35and 35 keeping the pawls from the ratchet teeth 36, disengages theclutch against the force of the springs 35;, and 35 so that if the cap34 is moved rightward by the shifter lever 34, the pawl ends become freeand the pawls will soon engage with the ratchet teeth by the aid of thesprings 35 and 35 thus engaging the clutch in action.

After the clutch has been engaged as above, the cam 14 and its holder 22are moved further upward, consequently the rack 29 rotates the shaft 37through the toothed wheel 30. Then there are provided the associatedearns 39, 40, 41, 42, and 43 arranged as a multiple sectioned drum 38 atthe other end of the shaft 37 and these cams face the acting rodsrespectively to actuate the following limit switches:

1the limit switch for changing rough cut to finish cut,

2the limit switch for relieving oil pressure within the oil cylinder 26,

3the limit switch for starting main electric motor, and

accompanying action,

4the limit switch for setting the upper limit of the motion of the cam14, and accompanying action,

the limit switch for settling the lower limit of the motion of the cam14, and accompanying action.

Thus there are five kinds of limit switches. The second switch is firstactuated by cam 40 and acting rod 2. An impulse from the second switchopens an exhaust valve, which permits relief of pressure within oilcylinder 26, allowing the saddle 11 to return to its original position.Then the third switch is actuated by cam 41 and acting rod 3 to startthe main electric motor (not illustrated).

If the main electric motor starts, its motion is transmitted from theshaft 44, through the toothed wheel 45 fixed thereto, to the toothedwheel 46 which is fixed on the sleeve fitted idly on the shaft 37, andfurther transmitted to rotate the toothed wheels 47 and 48, fixed on thesame sleeve, to the opposite direction with the shaft 44. Then theformer toothed wheel 47 rotates the toothed wheel 49 at the left-handside of the differential gear mechanism, while the latter toothed wheel48, through the toothed wheel 50 supported on the counter shaft C,rotates the toothed wheel 51 at the right-hand side of the samedifferential gear mechanism at the opposite direction compared to thedirection of rotation of the toothed wheel 49. Thus the pinion shaft 52at the middle of the same differential gear mechanism is rotated at aconsiderably reduced speed compared to that of the shaft 44.

The rotating motion thus reduced is transmitted, through the shaft 53upon which the pinion shafts are fixed, the toothed wheel 54 fixed onthe same shaft, the toothed wheel 55 fitted idly on the shaft 37 andpawls 35, 35', to the ratchet teeth 36 and therefore the shaft 37carrying the same ratchet teeth. Thus the shaft 37, through the toothedwheel 30 and the rack 29, drives the cam 14 in the reverse direction.

The clutch here used is purposely of ratchet type because it is neededto engage in one direction only; that is to say, the shaft 37 mustrotate freely when it is rotated by the oil pressure through the rack 29and the toothed wheel 30 and moreover the clutch must engage when themain electric motor starts and the cam 14 is driven in the reversedirection through the clutch and the gearing stated above. Thedifferential gearing is utilized for getting a large degree of speedreduction in a comparatively narrow space.

When the main electric motor starts as already described, the mechanismwhich transmits a special combined motion of rotation and reciprocationto the cutter spindle, also starts. And according to the upward motionof the cam 14, the cutting of teeth upon the work will proceed with atfirst one turn of rough cut, and then a finish out following. Suchchange of cut is made by the action of a change gear (not illustrated),for changing the position of the cutter saddle through the cam 14 by thelimit switch No. 1 actuated by the cam 39.

When the cam 14 reaches its up stroke end, the cutting of the teeth mustbe entirely finished. The limit switch No. 4 will control such point ofup stroke, being actuated by the cam 42. At the same time, the mainelectric motor is stopped by cutting olf the electric current and theoil cylinder 26 is actuated by the same limit switch to move the cam 14down.

When the cam 14 reaches its lowest position, which position has beencontrolled by the limit switch No. 5 actuated by the cam 43, the samelimit switch 5 cuts off the oil pressure to the oil cylinder 26 andstarts another oil cylinder 18 for making the cutter saddle 11 retire toits leftward stroke end to complete one cycle of gear cutting. At thatposition the Work is removed and next work is put on the work spindlefor starting a new cutting again.

The manners of the motion of the saddle 11 and the cam 14 are plotted inFIG. 6, in which the time T and the distance of movement L are shown onabscissa and ordinate respectively. In the diagram, Sdll means thesaddle 11, while 01114 the cam 14. And 0 means the term of oil pressuredrive while P that of positive drive.

Annexed is the simple explanation of the points 1, 2, 3, 4, 5, 6, 7, 8on the curve Sdll as well as the points a, b, c, d, e on the curve Cm14.

1The position of the saddle at its most remote place from the work,

2The position of the saddle when a limit switch actuated by the actingrod 19 brakes the oil cylinder 18,

3The position of the saddle when a limit switch actuated by the actingrod 20 cuts off the oil pressure to the oil cylinder 18,

4The position of the saddle when the cam 14 begins to move the saddletoward the work for rough cutting, just before, the oil drive is changedto positive drive,

5Rough cut begins,

6Rough cut is changed to finish cut,

7After the cutting has been finished, the retirement of the saddle bythe oil cylinder 18 begins,

8-The saddle retired at its initial starting position.

a The down stroke end from which the cam 14 is pushed up by the oilcylinder 26,

b The oil cylinder 26 is braked by the limit switch actuated by theacting rod 33, soon after, its oil pressure is cut off and positivedrive begins by the actuation of the limit switch actuated by cam 41,

c Rough cut is changed to finish cut,

d At the up stroke end, the cutting completes, and the cutter stops, atthe same time the cam 14 is moved down by the oil cylinder 26,

e The oil cylinder 26 sops and the cam 14 returns at the initialposition.

As may be seen in the diagram, the cam 14 and the cutter saddle 11 aredriven at high speed by high oil pressures when the saddle approaches toor is withdrawn from the work, so that the idle time is greatly reduced.But on the other hand when the real cutting is practiced, they are movedby a positive driving at a low speed and fixed precision, so that aprecise cut can be ensured.

Also since all cutting steps are controlled completely andautomatically, the efliciency will be enormously increased.

It is understood that suitable modifications may be made in thestructure as disclosed, provided such modifications come within thespirt and scope of the appended claims. Having now therefore fullyillustrated and described my invention, what I claim to be new anddesire to protect by Letters Patent is:

In an automatic electrically driven gear shaper wherein a cutter ispowered for cutting action and a cutter saddle is moved horizontally andradially toward and from the vertically fixed axis of a worktablemounted in a fixed frame and carrying a workpiece, hydraulic systemmeans for driving said saddle at high speeds during both its preliminarystrokes wherein it approaches the work cutting position, and during itsfinal strokes wherein it retires after cutting is completed, saidhydraulic system means including a horizontal axis hydraulic cylinderfixed to the frame, and carrying therewithin a piston and a cylinder rodwith an outer end of the latter fixed directly to a portion of saidcutter saddle, whereby said cylinder rod and cutter saddle moveunitarily and simultaneously with respect to said frame, and slowerspeed positive acting mechanical drive means for the saddle including avertically movable side face cam mounted on the frame, and a horizontalmotion transmission bar between and contacting the cam and saddle, saidmechanical drive means operable upon the cutter saddle with a slowerfeeding motion during the intermediate stroke between the preliminaryand the final strokes when said hydraulic means have been inactivated,the interchange in drive means from hydraulic to mechanical and viceversa being accomplished by means including a unitary multiple sectionedrotating drum cam with stationary horizontal axis, and located in anexposed accessible position at one end of the gear shaper, whichsequentially operates a plurality of acting rods, each rod controlling alimit switch, the sequence of action of the limit switches aiding in theprogramming of the control of the electric drive, the powering of thecutter, and the rotating of the workpiece, the requisite pressures inthe hydraulic system and the operative relationships of the positiveacting mechanical drive means.

References Cited by the Examiner UNITED STATES PATENTS 2,198,882 4/1940Monroe -10 2,374,901 5/1945 Sneed 90-1O 2,749,805 6/1956 Kendall 90-72,975,681 3/1961 Wildhaber 90-10 3,021,765 2/1962 Cobb 907 ANDREW R.JUHASZ, Primary Examiner.

LEON PEAR, Examiner.

